Air preheater



H. H. DOW

AIR PREHEATER Oct. 25, 1932.

'2 Sheets-Sheet Original Filed July 6, 1925 Alg /N E ATTORNEYS.

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06f. 25, 1932. H HD DOW 1,884,617

AIR PREHEATER Original Filed July 6l 1.925 2 Sheets-Sheet 2 INVENTOR.

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Patented Oct. 25, 1932 UNITED STATES PATENT OFFICE HERBERT H. DOW, OF MIDLAND', MICHIGAN, ASSIGNOR, BY MESNE-ASSIGNMENTS, TO AIR PBEHEATER CORPORATION, F NEW YORK, N. Y., A CORPORATION OF NEW YORK AIR YREHEATER Original application filed July 6, 1925, Serial No. 41,565. Divided and this application led November 16,

1926. Serial This application is a division of subjectmatter originally filed July 6, 1925 in Serial No. 41,565.

One particular field of use forthek present improved air preheater is as an apparat-us for utilizing the hot flue gases from a furnace to heat the air required in the combustion of the fuel used in such furnace. 1t will be understood, however, that such apparatus may lo be employed in various other fields where it is desired to interchange heat between two fluid media.

The following may be enumerated as objects of the invention, viz:

To utilize the heat of stack gases 1n an apparatus that will not be rendered inoperative by the corrosive fumes contained in said gases.

To provide a simple and compact mechanism for the purpose stated and one that will not require any great amount of power for its operation. Y

To use any heat absorbing material, irrespective of whether it be uniform in size,

shape or kind, or how it be arranged in chambers.

To obtain a long life for the preheater, because corrosion or disintegration of the heat 'absorbing material will not destroy the usefulness of the preheater. If the disintegrating particles collect and tend to obstruct the flow of the media through the packing, a cleaning will remove the small particles and the larger material may be used over again.

To obtain a high rate of heat transfer between the heat absorbing material and the media through turbulence and good scrubbing action caused by the irregular path that 40 the media have to take while flowing through the heat absorbing material.

To obtain a continuous transfer of heat from the hot media to the heat absorbing material, simultaneously with heat being transferred from other portions of the heat radiating material to the cold media through the use of a plurality of chambers.

To have a minimum number of chambers necessarily out of communication with either the hot or cold media at any one time by the use of an odd plurality of chambers.

To the accomplishment of the foregoing and related ends, the invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims, the annexed drawings and the following description setting forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

n In said annexed drawings Fig. 1 is a central vertical section on line 1 1 of Figure 2 through an air preheating apparatus embodying the present improvements; Fig. 2 is a top plan view thereof; and Fig. 8 is a transverse section of the same, taken on the plane indicated by the line 3 3, Fig. 1.

Fig. 4 is a perspective view of one of the valves, and

Fig. 5 is a horizontal section thereof, the line 1-1 showing the line corresponding to the section shown in Fig. 1.

The body of such illustrative apparatus comprises an odd plurality of circularly arranged chambers or compartments 1, formed by an outer cylindrical shell 2, an inner shell .3 concentric therewith, and the proper number of radial partitions. Such inner shell terminates short of the respective ends l and of the outer shell and is connected with such ends by means of similar valve cages 6 and 7, which are open laterally to provide for the free inliow or outflow of gases, as the case may be, to or from the compartments or chambers 1. Such valve cages at the same time constitute a simple construction for insuring a good joint between the respective ports and the shells 2 and 3.

Where the apparatus is disposed with its axis vertical, as shown, a grid 8 is provided near the bottom of each compartment., approximately on the level of the lower end of the inner shell 3 where the latter is connected with the lower valve cage 7. This grid serves to support suitable heat absorbing packing material which substantially fills each eom partment, this material as shown, conslstmg of a plurality of short iron rings 9 placed end upon end but in staggered relation so that the air or gas in traveling through the compartments necessarily has to follow a tortuous course. The radial partitions 10 whereby the annular space between shells 2 and 3 is subdivided into such plurality of longitudinally extending compartments are best shown in Fig. 3, it being understood that the aforesaid filling material is packed between these partitions.

Mounted in the respective valve cages 6 and 7 are rotary valves 12 and 13, respectively, thatare identical except that they project in o posite directions. Each valve, in other words, consists of a plate-like base 12a and 13a, upon which the valve proper is mounted, the latter being in the form of a cylindrical wall rising from such base but of smaller diameter save on one side, where it projects to the edge of the base and is provided with a port opening 12b, 13b. As shown in Figs. 4 and 5, the port opening` 12b is separated from the area above plate 12a by the curved plates 120 and the skew plates 12d, the latter merging into the annular plate segment 12e which has a depending flange 127c defining the upper end of the port opening 12b. The valves are fixed upon a common central shaft l5 that is journaled in suitable axially aligned bearings 16 within the shell 3. One end of said shaft, the upper as shown, projects beyond the corresponding end of the apparatus and has secured thereto a beveled gear 17 whereby the shaft with attached valve may be rotated at a predetermined rate.

The cylindrical body portion of the lower valve 13 has a close moving fit within a sleeve 20 which forms in effect one end of a duct 21 through which hot flue gas is supplied to the apparatus; while the body of the upper valve 12 similarly fits Within a sleeve 22 that forms in effect one endof a duct 23 through which the ue gases escape to the stack or chimney after passing through the apparatus. The

3. 5 annular space between sleeve 2O and the valve cage 7 is connected with a chamber or duct 24 through which the air, after it has passed through the apparatus, is led to the furnace or other point where it is to be used; while similarly connected with the annular space between sleeve 22 and valve cage 6 is a duct 25 through which the cold air is led into the apparatus. Ventilating fans 26 and 27, mounted on a common power driven shaft 28, are located in such duct 25, through which the cold air is thus admitted, and in duet 23, through which the flue gases are discharged to the stack, respectively, so as to force the flow of such air and gases to whatever extent may be necessary.

In operation, as the vertical shaft 15 rotates, the hot flue gases entering by way of duct 21 are caused to pass through port 13b in valve 13 into successive vertical compartments in the annular chamber l, whence they escape through port 12b of the upper valve 12 into the discharge duct 23. In thus passing through the compartments, these gases impart a considerable portion of their heat to the filling material 9 and this heat is then in turn taken up by the cold air entering the compartments through duct 25 and the annular space between sleeve 22 and valve cage 6. After becoming thus heated, the air is discharged fro-m the compartments through the annular space between the sleeve 20 and valve cage 7 into duet 24.

The form of the valve bodies 12 and 13 is such that the compartment or compartments of the chamber 1, through which the hot flue gas is being conducted, will be completely shut olf against passage of the air therethrough and commingling of the latter with the flue gas accordingly prevented. It will also be understood that the length of chamber 1 may be varied to suit the requirements of the particular installation, the longer the path of travel 0f the hot gas and cold air, the more complete the heat interchange therebetween.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention z 1. The combination of a plurality of compartments, heat absorbing material dispod therein, means for supplying two fluid media of different temperatures to, and for discharging same from, said compartments, and interconnected rotary valves continuously rotatable in the same direction and operating to control the flow of such mediav through said compartments, said valves being arranged and constructed to open each compartment in succession to the How of one such medium and then the other Without interrupting or bypassing such flow.

2. The combination of a plurality of conipartments, heat absorbing material disposed therein, means for supplying two Huid media of different temperatures to, and for discharging same from, said compartments, and interconnected rotary valves continuously rotatable in the same direction and operating to control the flow of such media through said compartments, said valves being arranged and constructed to open each compartment in succession to the flow of one such medium and then the other Without interrupting or bypassing such flow and the number of said compartments being sufficiently great to permit more than one thereof at a time to be. open to the flow of such media, respectively.

3. rlhe combination with a plurality of stationary compartments, heat absorbing material disposed therein` means for supplying tivo fluid media of different temperatures to, and for discharging same from, opposite ends, respectively, of said compartments, and interconnected rotary valves continuously rotatable in the same direction and associated with such ends and operating in unison to control the flow of such media through said compartments, said valves being arranged and cons 'ucted to open each compartment in succession to the flow of one such medium and then the other Without interrupt-ing or ley-passing such flow.

d. The combination With a plurality of stationary compartments, heat absorbing materi al disposed therein. means for supplying two fluid media of different temperatures to, and for discharging same from, opposite ends, respectively, of said compartments, and interconnected rotary valves continuously rotatable in the same direction and associated with such ends and operating in unison to control the flouv of such media through said compartments, said valves being arranged and constructed to open each compartment in succession to the floiv of one such medium and then the other Without interrupting or lay-passing such fiov: and the number of said compartments being suficiently great to permit more than one thereof at a time to be open to the flow of such media, respectively.

5. rl'he combination of a plurality of circularly arranged compartments, heat absorbing material disposed therein, and two rotary valves located at the respective ends of said compartments and rotating in unison continuously in the same direction relatively thereto. to control the flow of fluid media through said compartments.

6. A regenerative heating device comprising a stationary regenerative material having passages through the same, a plurality of chifumcls for different fluids at the ends of said passages, one channel at either end passing through another channel at the same end and a plurality of coaxially mounted interconnect-ed continuously rotating conduit forming devices to successively establish communication betvfeen each of said cha nels and different passages in said regenerative material.

7. il, regenerative heating device comprising stationary regenerative material having passages through the saine, a plurality of stationary channels for different fluids at the ends of said passages, one channel at either end passing through another channel at the same end and a plurality of ooaXially mounted interconnected continuously rotating conduit forming devices to successively establish communication between each of said channels and different passages in said regenerative material.

8. A. regenerative heating device comprising a stationary regenerative material having pas ages through the same, concentric supply and discharge cn annels for a duid to be heated and a fluid giving on' heat, a valvular device having openings through the same affording communication between each of said channels and some of the passages through the regenerative material and means to rotate said valvular device.

9. regenerative heating device comprising a stationary frame-Work, compartments in said frame-Work, regenerative material in said compartments, a supply channel and a discharge channel for a fluid to be heated, a supply channel and a discharge channel for a fluid giving loii heat, a valvular device contr( communication bet-Ween the compartand the channels, said valvular device in given position controlling communication between the channels for the. fluid to be heated and certain compartments and simultaneousy controlling communication between the channels for the fluid giving-olf heat and other compartments than said certain compartments, and means to continuously rotate said valvular device.

l0. A regenerative heating device comprising a cylindrical stationary frame-Work, regenerative material in said frame-Work having passages through the same, supply and discharge channels for a fluid to be heated and a fluid giving olf heat, a valvular device of generally circular formation at each end of said frame-Work having openings through the same and operating to control communication between said channels and said passages, a common shaft for the valvular devices, said shaft extending through the center of said frame-Work and means to rotate said shaft.

l1. A regenerative heating device comprising a stationary frame-Work, regenerative material in said frame-Work having passages through the same, the ends of said regenerative material determining planes, a supply channel and a discharge channel for a fluid situated at opposite ends of said regenerative material, a supply channel and a discharge channel for a second fluid also situated at opposite ends of said regenerative material, the last mentioned supply channel and discharge channel comprising coaxially mounted rotatable conduit forming valvular devices, said valvular devices in a given position controlling communication between the fluid passing through the same and certain passages of said regenerative material and llO simultaneously permitting communication between the first mentioned supply channel and discharge channel through other passages of the regenerative material, the channels comprising the valvular devices being arranged to extend within the first mentioned supply channel and discharge channel and means to continuously rotate said valvular devices in unison.

12. A regenerative heating device comprising stationary regenerative material, conduits for feeding different temperature fluids to said regenerative material and a continuously rotating valvular device having openings in the same for selectively feeding said fluids to said regenerative material.

13. A regenerative heating device comprising supply and discharge channels for one fluid, supply and discharge channels for a second fluid, a stationary regenerative material comprising a plurality of passages, and continuously rotating conduit forming means to cause one fluid to pass through the first mentioned channels and through different passages at different times and to cause the second fluid to pass through the second mentioned channels and through different passages at different times.

14. A regenerative heating device comprising supply and discharge channels for one fluid, supply and discharge channels for a second fluid, a stationary regenerative material comprising a plurality of passages, and a plurality of interconnected continuously rotating conduit forming devices to cause one fluid to flow through the first mentioned channels and through different passages at different times and to cause the second fluid to pass through the second mentioned channels and through different passages at different times, the passages through which the first fluid passes at any time being different passages than those through which the second fluid passes.

15. A regenerative heating device comprising stationary regenerative material having regenerative passages through the same, supply and discharge channels for a fluid to be heated and a fluid giving off heat, a member having openings in the same, and means to continuously rotate said member to afford successive communication between the supply and discharge channels for each fluid and different regenerative passages.

16. A furnace air preheater comprising furnace gas flues adapted to be connected with a furnace and a stack and a flue adapted to be connected to feed air to the furnace, a series of heat exchange masses having passages therethrough and a rotary conduit mechanism cooperating therewith arranged to connect the furnace gas flues and the air flue successively and alternately with the passages through the heat exchange masses.

17. A furnace air preheater comprising a stationary casing having partitions therein forming separated passages through the casing, heatexchange material in said passages, flues for furnace gas leading from the furnace and to a stack, a flue for air leading to the furnace, and a power driven rotary conduit mechanism arranged to connect the furnace gas flues successively through a part of said passages and simultaneously connect the air flue with the exterior atmosphere through other passages.

18. A regenerative heating device comprising stationary regenerative material, and means for feeding different ten'iperature fluids to said regenerative material comprising a continuously rotating valvular device having openings in the same for selectively feeding said fluids to said regenerative material.

19. A regenerative heating device comprising supply and discharge channels for one fluid, a discharge channel for a second fluid, a stationary regenerative material comprising a plurality of passages, and continuously rotating conduit forming means to cause one fluid to pass through the first mentioned channels and through different passages at different times and to cause the second fluid to pass through different passages at different times and through the second mentioned discharge channel.

20. A regenerative heating device comprising a stationary regenerative material having passages through the same, a plurality of channels for different fluids at the ends of said passages, one channel at one end passing through another channel at the me end and a plurality of coaxially mounted interconnected continuously rotating valvular devices cooperating with said channels to successively establish oon'imnnieation with different passages in said regenerative material.

21. In an air heater of the regenerative type, the combination of a casing having a gas inlet and out-let and an air inlet and outlet always in comnninication therewith and rotatable means separating the gas inlet and outlet from the air inlet and outlet in all positions of rotation.

22. In an air heater of the regenerative type, the combination of a tubular casing, regenerative elements housed therein and dividing the casing into a plurality of longitudinal passages. a rotatable blanking element at each end of the casing, the end of the casing beyond one of said blanking elements constituting a `ras inlet and the other end a gas outlet. and an annular compartment around each blanking element, one of which constitutes an air inlet and the other an air outlet, said blanlring elements being adapted to separate the gas inlet and outlet from the air inlet and outlet.

23. In an air heater of the regenerative type, the combination of a casing having a lll stationary air inlet and outlet and a stationary gas inlet and outlet, stationary regenerative elements within said casing, and rotatable blanling members separating the gas inlet and outlet from the air inlet and outlet in all positions of rotation.

24;. ln a heat exchanger, a casing, regenerative material in said casing having passages therethrough, means for supplying two fluid media of different temperatures to, and for discharging same from, said regenerative material, and valve means unidirectionally rotatable to control the flouT of such media through said regenerative material, said valve means being arranged and constructed to communicate said passages in succession to the flow of one medium and then the other.

25. In a heat exchanger, a cylindrical casing, regenerative material disposed therein, means for supplying fluid media of different temperatures to, and for discharging same from, said casing, and valve means rotatable unidirectionally with respect to said regenerative material and controlling flow of said fluid media through said regenerative material.

26. ln a. heat exchanger, a cylindrical casing, a plurality of circularly arranged compartments therein, regenerative material disposed in each of said compartments, means for supplying fluid media of different temperatures to, and for discharging same from, said compartments, and valve means rotatable unidirectionally With respect to said compartments and controlling flow of said fluid media through said compartments.

27. In a heat exchanger, a cylindrical casing, a plurality of circularly arranged compartments therein, regenerative material disposed in said compartments, means for supplying fluid media of different temperatures to, and for discharging same from, said compartments, and valve means rotatable unidirectionally wi th respect to said compartments and controlling flow of said fluid media through said compartments, said valve means being arranged and constructed to open each compartment in succession to the flow of one such medium and then the other Without interrupting or bypassing such HOW.

28. A regenerative heating device comprising stationary compartments each containing regenerative material, conduits for feeding different temperature fluids to said compartments, and a valvular device rotatable unidirectionally and having ports for selectively feeding said fluids to said compartments.

29. The combination With a plurality of stationary compartments, heat absorbing material disposed therein, means for supplying two fluid media of different temperatures to, and for discharging same from, opposite ends, respectively, of said compartments, and

continuously moving valves associated With such ends and operating in unison to control the flow of such media through said compartments, said valves being arranged and constructed to open each compartment in succession to the flow of one such medium and then the other Without interrupting or by-passing such flow, and the number of said compartments being suciently great to permit more than one thereof at a time to be open to the flow of such media, respectively.

Signed by me this l0 day of November,

HERBERT H. DOlV. 

